r12d 142 arch/x86/entry/calling.h xorl %r12d, %r12d /* nospec r12 */ r12d 57 arch/x86/include/asm/inst.h .ifc \r32,%r12d r12d 107 tools/perf/arch/x86/util/perf_regs.c SDT_NAME_REG(r12d, r12),